The present invention relates to a remote-readable identification tags and methods of remote-readable identification e.g. using radio waves.
A remote-readable identification tag (Systems “MOBY”), which has a digitally stored identification number of up to 40 bits in length, is known, for example, from Siemens-Welt 6/98 or from advertising publications of Siemens AG. The digital identification number is implemented using multiple resonance circuits, excitable by radio waves (“radio frequency identification tags” or “RFID tags”), which are present on the identification tags. The radio waves (typically in the range from kHz to GHz, particularly from MHz to GHz) are at 125 kHz for system “MOBY-F”, for example, and are at 433 MHz for “MOBY-V”. Each resonance circuit corresponds to the representation of one bit (“1 bit RFID tag”). Multiple resonance circuits are integrated into an identification tag in accordance with the length of the identification number.
Until now, the data has been read out in that a pulse is transmitted to the identification tag, at 125 kHz for MOBY-F, for example, and the individual 1 bit RFID tags then emit pulses at essentially the same wavelength sequentially, i.e., with a time delay one after another. The identification number results in the reading device through reception of the sequential radio signals. The sequential emission of the signals of the individual 1 bit RFID tags is implemented by, inter alia, differently dimensioned delay devices.